[英]Powershell array is not cleared
My source code: 我的源代码:
# $arr = @(); results in same behaviour
$arr = New-Object System.Collections.ArrayList;
$arr.Count;
$arr += "z";
$arr.Count;
$arr.Clear();
$arr.Count;
Output: 输出:
0 0
1 1
1 1
Powershell does some array-casting trickery when you do +=
, so the easy solution is to do $arr.Add("z")
. 当你执行+=
,Powershell会做一些数组转换$arr.Add("z")
,所以简单的解决方案是执行$arr.Add("z")
。 Then $arr.Clear()
will act like you expect. 然后$arr.Clear()
会像你期望的那样行事。
To clarify: 澄清:
@()
is a Powershell array. @()
是一个Powershell数组。 It uses +=
, but you can't Clear
it. 它使用+=
,但你无法Clear
它。 (You can, however, do $arr = @()
again to reset it to an empty array.) (但是,您可以再次执行$arr = @()
将其重置为空数组。) ArrayList
is the .NET collection. ArrayList
是.NET集合。 It uses .Add
, and you can Clear
it, but for some reason if you +=
it, Powershell does some weird array coercion. 它使用.Add
,你可以Clear
它,但出于某种原因,如果你+=
它,Powershell会做一些奇怪的数组强制。 (If any experts care to comment on this, awesome.) (如果有任何专家对此发表评论,真棒。)
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